The present invention relates to a locking device for a vehicle seat.
It is known for a locking device to be part of an articulated fitting for a motor vehicle seat. An inclination adjustment provided by such a fitting takes place between a lower part of the fitting, which is fixed to the seat part, and an upper part of the fitting, which is fixed to the backrest. The lower part of the fitting and the upper part of the fitting are locked, except when the backrest is being pivoted, by means of a latch mounted on the lower part of the fitting. The latch is secured by a prestressed, eccentric clamping element. An intercepting element having a concentric intercepting surface serves to support the latch in the event of a crash. Due to manufacturing tolerances, especially in the case of finely stepped inclination adjustment, the distance between the latch and the intercepting element may result in it no longer being possible to absorb the crash load.
One aspect of the present invention is the provision of an improved locking device of the above-described type. In accordance with this aspect, the locking device is for releasably restricting relative movement between first and second parts of a vehicle seat, or the like, that are mounted for moving relative to one another, and the locking device includes first and second toothed elements mounted for alternately being engaged to one another and disengaged from one another. The first toothed element is for being connected to the first part of the vehicle seat, the second toothed element is for being connected to the second part of the vehicle seat, and the locking device is for allowing the relative movement between the first and second parts of the vehicle seat while the first and second toothed elements are disengaged from one another. The locking device further includes a clamping element that generally keeps the first and second toothed elements engaged to one another while the locking device is in a locked state. The first and second toothed elements restrict relative movement between the first and second parts of the vehicle seat while the first and second toothed elements are kept engaged to one another. The locking device additionally has an intercepting element including at least two intercepting surfaces. In the event of a crash, the intercepting element supports the first toothed element via at least one of the intercepting surfaces to keep the first and second toothed elements engaged to one another.
In accordance with one nonlimiting example of the present invention, the intercepting element is for supporting the first toothed element via a first intercepting surface of the two intercepting surfaces, rather than via a second intercepting surface of the two intercepting surfaces, to keep the first and second toothed elements engaged to one another when the locking device has first tolerances and the crash occurs. Similarly and in accordance with another nonlimiting example of the present invention, the intercepting element is for supporting the first toothed element via the second intercepting surface, rather than via the first intercepting surface, to keep the first and second toothed elements engaged to one another when the locking device has second tolerances, which are different from the first tolerances, and the crash occurs.
On account of the intercepting element having at least two different intercepting surfaces, the functioning of the intercepting element can be ensured and the loss of contact of the toothing minimized even at relatively large tolerances. Two or more intercepting surfaces can be provided. The intercepting surfaces, which are formed preferably concentrically or at least approximately concentrically with the pivot axis of the intercepting element, are preferably arranged adjacent to each other on the intercepting element, i.e. are connected to each other, preferably have small central angles, i.e. an angle of a few degrees, and preferably form a convex contour on the intercepting element. Each of these measures increases the probability of one of the intercepting surfaces taking up the smallest possible distance from the first toothed element, i.e. being aligned parallel to a bearing surface of said toothed element. This preferably applies to just one intercepting surface.
In a preferred embodiment, the two or more intercepting surfaces are at a different distance from the pivot axis of the intercepting element. Radial tolerances can also be compensated for by a slightly eccentric shape of the intercepting element. In this case, steps can be provided between the intercepting surfaces, which steps somewhat reinforce the eccentric shape of the intercepting element.
A vehicle seat according to the invention, in particular a motor vehicle seat, has at least one vehicle seat adjuster or a seat-fixing means on the vehicle floor having a locking device according to the invention. A vehicle seat adjuster of this type may, for example, be a latching fitting having combined inclination adjustment and a free-pivoting function, where the locking device is released in both cases, or may be any desired articulated fitting, for example a tumbling fitting where the locking device is released only for the free-pivoting process. The vehicle seat adjuster may optionally also be a longitudinal adjuster, height adjuster or inclination adjuster. The locking device according to the invention may also be used for the seat-fixing means by which the vehicle seat is fixed to the vehicle floor. The toothed elements which are used can be pivotable latches or latches mounted in a floating manner and having a lateral toothing, displaceable locking bars having a toothing at the front end, gearwheels having an external toothing, hollow wheels having an internal toothing or suitable combinations thereof.